<h2>DESCRIPTION</h2>

<em>d.correlate</em> displays graphically the results of a
<em>r.stats</em> analysis run on two raster map layers. This module
highlights the correlation (or lack of it) among data
layers (scattergram).

<p>The results are displayed in the active display frame on
the user's graphics monitor. <em>d.correlate</em> erases
the active frame before displaying results. If no graphics monitor
is open, a file <tt>map.png</tt> is generated in the current directory.

<h2>NOTES</h2>

If three or four map layers are specified, the correlation
among each combination of two data layers is displayed.

<h2>EXAMPLE</h2>

Scatterplot of two LANDSAT TM7 channels (North Carolina sample dataset):
<p><div class="code"><pre>
g.region raster=lsat7_2002_30 -p
d.correlate map=lsat7_2002_30,lsat7_2002_40
</pre></div>

<center>
<img src="d_correlate_plot.png" border=1 alt="Scatterplot of two LANDSAT TM7 channels"><br>
Scatterplot of two LANDSAT TM7 channels
</center>

<h2>SEE ALSO</h2>

<em>
<a href="d.text.html">d.text</a>,
<a href="d.graph.html">d.graph</a>,
<a href="r.coin.html">r.coin</a>,
<a href="r.regression.line.html">r.regression.line</a>,
<a href="r.stats.html">r.stats</a>
</em>

<h2>AUTHORS</h2>

Michael Shapiro,
<a href="http://www.cecer.army.mil/">U.S.Army Construction Engineering Research Laboratory</a>
<p>Rewritten to GRASS 6 (from csh to sh) by Markus Neteler; from sh to Python by Glynn Clements

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